A wide variety of electronic devices incorporate displays to present an image to a viewer. Made up of one or more transistors per pixel, thin-film transistor (TFT) backplane arrays can be used to activate the portions of a display that present an image to the viewer. Since the performance of a display is dependent upon the backplane array used to drive the display, backplane arrays are typically tested to identify electrical defects such as short circuits, open circuits, or other manufacturing defects.
One known method of testing backplane arrays includes connecting one or more wires to each transistor in each pixel element of a backplane array. In high-resolution displays comprising hundreds of thousands, or even millions, of transistors, the addition of these wires can significantly increase the cost and complexity of the backplane array. In applications where the space provided for a backplane array is limited, the need to include additional wires or other connections to each transistor can severely limit the number of transistors that can be included in the backplane array, and thus the number of pixel elements that can be used in the display.